Wilt the spinach by adding it to a large pot of boiling water while making sure it’s fully submerged, and simmering it with a lid on for 1 minute to 90 seconds, drain well and leave it to cool in a colander until needed.

Now make the cheesy béchamel sauce. Melt the butter in a large saucepan, then add the minced shallot and garlic and cook over very low heat for 3 minutes while stirring, add the flour and mix to combine the ingredients into a paste, continue cooking while stirring for about 2 minutes, then add 1/2 cup of the milk and whisk to blend, after that pour in the rest of the milk and continue whisking until well blended.

Add the bay leaf and 1/4 tsp of nutmeg and cook while stirring over low heat until thickens, which will take about 10 minutes Remove the bay leaf and discard it. Now add the grated gruyere cheese and continue stirring until its is fully incorporated. You can either leave the sauce as it is or run it through a blender to get silky smooth results, which is what I did. Then return to the the saucepan, add the salt and turn the heat on low.

Now take the spinach and squeeze out as much liquid out of it as possible and stir it into the sauce, continue cooking over very low heat for 10 minutes stirring often. Take off the heat and serve.